dummy-ups: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/sbin/dummy-ups - from package: nut

You may install the required package with command yum install {package}

Error in other languages:
dummy-ups: bevel nie gevind nie
dummy-ups: comandă negăsită
dummy-ups: comando não encontrado
dummy-ups: commande introuvable
dummy-ups: command not found
dummy-ups: käsku ei ole
dummy-ups: không tìm thấy lệnh
dummy-ups: komanda nerasta
dummy-ups: Kommando nicht gefunden.
dummy-ups: kommandot finns inte
dummy-ups: komut yok
dummy-ups: nie znaleziono polecenia
dummy-ups: níor aimsíodh an t-ordú
dummy-ups: no se encontró la orden
dummy-ups: no s'ha trobat l'ordre
dummy-ups: opdracht niet gevonden
dummy-ups: parancs nem található
dummy-ups: perintah tidak ditemukan
dummy-ups: príkaz nenájdený
dummy-ups: příkaz nenalezen
dummy-ups: команда не найдена
dummy-ups: командата не е открита
dummy-ups: 命令找不到
dummy-ups: コマンドが見つかりません